Method and apparatus to facilitate support for multi-radio coexistence

ABSTRACT

A method of wireless communication includes determining a frame offset between communications of a first communication resource (e.g., an LTE radio) and communications of a second communication resource (e.g., a Bluetooth or WLAN radio). The method also includes determining potential time slot configurations for the communications of the second communication resource. A time slot configuration is selected from the determined potential time slot configurations, to reduce degradation of the first communication resource due to conflicting time slots between the first communication resource and the second communication resource, based on the determined frame offset. The selection may be based on the determined frame offset.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 61/370,717 filed Aug. 4, 2010, entitled “METHOD ANDAPPARATUS TO FACILITATE SUPPORT FOR MULTI-RADIO COEXISTENCE,” thedisclosure of which is expressly incorporated herein by reference in itsentirety.

TECHNICAL FIELD

The present description is related, generally, to multi-radio techniquesand, more specifically, to coexistence techniques for multi-radiodevices.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, data, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., bandwidth and transmit power). Examples of suchmultiple access systems include code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, 3GPP Long Term Evolution (LTE)systems, and orthogonal frequency division multiple access (OFDMA)systems.

Generally, a wireless multiple-access communication system cansimultaneously support communication for multiple wireless terminals.Each terminal communicates with one or more base stations viatransmissions on the forward and reverse links. The forward link (ordownlink) refers to the communication link from the base stations to theterminals, and the reverse link (or uplink) refers to the communicationlink from the terminals to the base stations. This communication linkmay be established via a single-in-single-out, multiple-in-single-out ora multiple-in-multiple out (MIMO) system.

Some conventional advanced devices include multiple radios fortransmitting/receiving using different Radio Access Technologies (RATs).Examples of RATs include, e.g., Universal Mobile TelecommunicationsSystem (UMTS), Global System for Mobile Communications (GSM), cdma2000,WiMAX, WLAN (e.g., WiFi), Bluetooth, LTE, and the like.

An example mobile device includes an LTE User Equipment (UE), such as afourth generation (4G) mobile phone. Such 4G phone may include variousradios to provide a variety of functions for the user. For purposes ofthis example, the 4G phone includes an LTE radio for voice and data, anIEEE 802.11 (WiFi) radio, a Global Positioning System (GPS) radio, and aBluetooth radio, where two of the above or all four may operatesimultaneously. While the different radios provide usefulfunctionalities for the phone, their inclusion in a single device givesrise to coexistence issues. Specifically, operation of one radio may insome cases interfere with operation of another radio through radiative,conductive, resource collision, and/or other interference mechanisms.Coexistence issues include such interference.

This is especially true for the LTE uplink channel, which is adjacent tothe Industrial Scientific and Medical (ISM) band and may causeinterference therewith It is noted that Bluetooth and some Wireless LAN(WLAN) channels fall within the ISM band. In some instances, a Bluetootherror rate can become unacceptable when LTE is active in some channelsof Band 7 or even Band 40 for some Bluetooth channel conditions. Eventhough there is no significant degradation to LTE, simultaneousoperation with Bluetooth can result in disruption in voice servicesterminating in a Bluetooth headset. Such disruption may be unacceptableto the consumer. A similar issue exists when LTE transmissions interferewith GPS. Currently, there is no mechanism that can solve this issuesince LTE by itself does not experience any degradation

With reference specifically to LTE, it is noted that a UE communicateswith an evolved NodeB (eNB; e.g., a base station for a wirelesscommunications network) to inform the eNB of interference seen by the UEon the downlink. Furthermore, the eNB may be able to estimateinterference at the UE using a downlink error rate. In some instances,the eNB and the UE can cooperate to find a solution that reducesinterference at the UE, even interference due to radios within the UEitself. However, in conventional LTE, the interference estimatesregarding the downlink may not be adequate to comprehensively addressinterference.

In one instance, an LTE uplink signal interferes with a Bluetooth signalor WLAN signal. However, such interference is not reflected in thedownlink measurement reports at the eNB. As a result, unilateral actionon the part of the UE (e.g., moving the uplink signal to a differentchannel) may be thwarted by the eNB, which is not aware of the uplinkcoexistence issue and seeks to undo the unilateral action. For instance,even if the UE re-establishes the connection on a different frequencychannel, the network can still handover the UE back to the originalfrequency channel that was corrupted by the in-device interference. Thisis a likely scenario because the desired signal strength on thecorrupted channel may sometimes be higher be reflected in themeasurement reports of the new channel based on Reference SignalReceived Power (RSRP) to the eNB. Hence, a ping-pong effect of beingtransferred back and forth between the corrupted channel and the desiredchannel can happen if the eNB uses RSRP reports to make handoverdecisions.

Other unilateral action on the part of the UE, such as simply stoppinguplink communications without coordination of the eNB may cause powerloop malfunctions at the eNB. Additional issues that exist inconventional LTE include a general lack of ability on the part of the UEto suggest desired configurations as an alternative to configurationsthat have coexistence issues. For at least these reasons, uplinkcoexistence issues at the UE may remain unresolved for a long timeperiod, degrading performance and efficiency for other radios of the UE.

SUMMARY

A method for wireless communications is offered. The method includesdetermining a frame offset between communications of a firstcommunication resource and communications of a second communicationresource. The method also includes determining potential time slotconfigurations for the communications of the second communicationresource. The method further includes selecting a time slotconfiguration, from the determined potential time slot configurations,that reduces degradation of the first communication resource due toconflicting time slots between the first communication resource and thesecond communication resource, based on the determined frame offset.

An apparatus operable in a wireless communication system includes meansfor determining a frame offset between communications of a firstcommunication resource and communications of a second communicationresource. The apparatus also includes means for determining potentialtime slot configurations for the communications of the secondcommunication resource. The apparatus further includes means forselecting a time slot configuration, from the determined potential timeslot configurations, that reduces degradation of the first communicationresource due to conflicting time slots between the first communicationresource and the second communication resource, based on the determinedframe offset.

A computer program product configured for wireless communication isoffered. The computer program product includes a computer-readablemedium having program code recorded thereon. The program code includesprogram code to determine a frame offset between communications of afirst communication resource and communications of a secondcommunication resource. The program code also includes program code todetermine potential time slot configurations for the communications ofthe second communication resource. The program code further includesprogram code to select a time slot configuration, from the determinedpotential time slot configurations, that reduces degradation of thefirst communication resource due to conflicting time slots between thefirst communication resource and the second communication resource,based on the determined frame offset.

An apparatus configured for operation in a wireless communicationnetwork is offered. The apparatus includes a memory and a processor(s)coupled to memory. The processor(s) is configured to determine a frameoffset between communications of a first communication resource andcommunications of a second communication resource. The processor(s) isalso configured to determine potential time slot configurations for thecommunications of the second communication resource. The processor(s) isfurther configured to select a time slot configuration, from thedetermined potential time slot configurations, that reduces degradationof the first communication resource due to conflicting time slotsbetween the first communication resource and the second communicationresource, based on the determined frame offset.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify correspondingly throughout.

FIG. 1 illustrates a multiple access wireless communication systemaccording to one aspect.

FIG. 2 is a block diagram of a communication system according to oneaspect.

FIG. 3 illustrates an exemplary frame structure in downlink Long TermEvolution (LTE) communications.

FIG. 4 is a block diagram conceptually illustrating an exemplary framestructure in uplink Long Term Evolution (LTE) communications.

FIG. 5 illustrates an example wireless communication environment.

FIG. 6 is a block diagram of an example design for a multi-radiowireless device.

FIG. 7 is graph showing respective potential collisions between sevenexample radios in a given decision period.

FIG. 8 is a diagram showing operation of an example Coexistence Manager(CxM) over time.

FIG. 9 is a block diagram of a system for providing support within awireless communication environment for multi-radio coexistencemanagement according to one aspect of the present disclosure.

FIG. 10 illustrates radio interference between a Long Term Evolutionradio and a Bluetooth radio.

FIG. 11 illustrates radio interference between a Long Term Evolutionradio and a Bluetooth radio.

FIG. 12 is a flow diagram for determining a coexistence policy forcommunication resource operation according to one aspect of the presentdisclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure provide techniques to mitigatecoexistence issues in multi-radio devices, where significant in-devicecoexistence problems can exist between, e.g., the LTE and IndustrialScientific and Medical (ISM) bands (e.g., for Bluetooth/WLAN). Asexplained above, some coexistence issues persist because an eNB is notaware of interference on the UE side that is experienced by otherradios. According to one aspect, the UE declares a Radio Link Failure(RLF) and autonomously accesses a new channel or Radio Access Technology(RAT) if there is a coexistence issue on the present channel. The UE candeclare a RLF in some examples for the following reasons: 1) UEreception is affected by interference due to coexistence, and 2) the UEtransmitter is causing disruptive interference to another radio. The UEthen sends a message indicating the coexistence issue to the eNB whilereestablishing connection in the new channel or RAT. The eNB becomesaware of the coexistence issue by virtue of having received the message.

The techniques described herein can be used for various wirelesscommunication networks such as Code Division Multiple Access (CDMA)networks, Time Division Multiple Access (TDMA) networks, FrequencyDivision Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA)networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms“networks” and “systems” are often used interchangeably. A CDMA networkcan implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), cdma2000, etc. UTRA includes Wideband-CDMA (W-CDMA) andLow Chip Rate (LCR). cdma2000 covers IS-2000, IS-95 and IS-856standards. A TDMA network can implement a radio technology such asGlobal System for Mobile Communications (GSM). An OFDMA network canimplement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11,IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM arepart of Universal Mobile Telecommunication System (UMTS). Long TermEvolution (LTE) is an upcoming release of UMTS that uses E-UTRA. UTRA,E-UTRA, GSM, UMTS and LTE are described in documents from anorganization named “3rd Generation Partnership Project” (3GPP). cdma2000is described in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). These various radio technologies andstandards are known in the art. For clarity, certain aspects of thetechniques are described below for LTE, and LTE terminology is used inportions of the description below.

Single carrier frequency division multiple access (SC-FDMA), whichutilizes single carrier modulation and frequency domain equalization isa technique that can be utilized with various aspects described herein.SC-FDMA has similar performance and essentially the same overallcomplexity as those of an OFDMA system. SC-FDMA signal has lowerpeak-to-average power ratio (PAPR) because of its inherent singlecarrier structure. SC-FDMA has drawn great attention, especially in theuplink communications where lower PAPR greatly benefits the mobileterminal in terms of transmit power efficiency. It is currently aworking assumption for an uplink multiple access scheme in 3GPP LongTerm Evolution (LTE), or Evolved UTRA.

Referring to FIG. 1, a is multiple access wireless communication systemaccording to one aspect is illustrated. An evolved Node B 100 (eNB)includes a computer 115 that has processing resources and memoryresources to manage the LTE communications by allocating resources andparameters, granting/denying requests from user equipment, and/or thelike. The eNB 100 also has multiple antenna groups, one group includingantenna 104 and antenna 106, another group including antenna 108 andantenna 110, and an additional group including antenna 112 and antenna114. In FIG. 1, only two antennas are shown for each antenna group,however, more or fewer antennas can be utilized for each antenna group.A User Equipment (UE) 116 (also referred to as an Access Terminal (AT))is in communication with antennas 112 and 114, while antennas 112 and114 transmit information to the UE 116 over a downlink (DL) 120 andreceive information from the UE 116 over an uplink (UL) 118. The UE 122is in communication with antennas 106 and 108, while antennas 106 and108 transmit information to the UE 122 over a downlink (DL) 126 andreceive information from the UE 122 over an uplink 124. In an FDDsystem, communication links 118, 120, 124 and 126 can use differentfrequencies for communication. For example, the downlink 120 can use adifferent frequency than used by the uplink 118.

Each group of antennas and/or the area in which they are designed tocommunicate is often referred to as a sector of the eNB. In this aspect,respective antenna groups are designed to communicate to UEs in a sectorof the areas covered by the eNB 100.

In communication over the downlinks 120 and 126, the transmittingantennas of the eNB 100 utilize beamforming to improve thesignal-to-noise ratio of the uplinks for the different UEs 116 and 122.Also, an eNB using beamforming to transmit to UEs scattered randomlythrough its coverage causes less interference to UEs in neighboringcells than a UE transmitting through a single antenna to all its UEs.

An eNB can be a fixed station used for communicating with the terminalsand can also be referred to as an access point, base station, or someother terminology. A UE can also be called an access terminal, awireless communication device, terminal, or some other terminology.

FIG. 2 is a block diagram of an aspect of a transmitter system 210 (alsoknown as an eNB) and a receiver system 250 (also known as a UE) in aMIMO system 200. In some instances, both a UE and an eNB each have atransceiver that includes a transmitter system and a receiver system. Atthe transmitter system 210, traffic data for a number of data streams isprovided from a data source 212 to a transmit (TX) data processor 214.

A MIMO system employs multiple (NT) transmit antennas and multiple (NR)receive antennas for data transmission. A MIMO channel formed by the NTtransmit and NR receive antennas may be decomposed into NS independentchannels, which are also referred to as spatial channels, whereinNS≦min{NT, NR}. Each of the NS independent channels corresponds to adimension. The MIMO system can provide improved performance (e.g.,higher throughput and/or greater reliability) if the additionaldimensionalities created by the multiple transmit and receive antennasare utilized.

A MIMO system supports time division duplex (TDD) and frequency divisionduplex (FDD) systems. In a TDD system, the uplink and downlinktransmissions are on the same frequency region so that the reciprocityprinciple allows the estimation of the downlink channel from the uplinkchannel. This enables the eNB to extract transmit beamforming gain onthe downlink when multiple antennas are available at the eNB.

In an aspect, each data stream is transmitted over a respective transmitantenna. The TX data processor 214 formats, codes, and interleaves thetraffic data for each data stream based on a particular coding schemeselected for that data stream to provide coded data.

The coded data for each data stream can be multiplexed with pilot datausing OFDM techniques. The pilot data is a known data pattern processedin a known manner and can be used at the receiver system to estimate thechannel response. The multiplexed pilot and coded data for each datastream is then modulated (e.g., symbol mapped) based on a particularmodulation scheme (e.g., BPSK, QSPK, M-PSK, or M-QAM) selected for thatdata stream to provide modulation symbols. The data rate, coding, andmodulation for each data stream can be determined by instructionsperformed by a processor 230 operating with a memory 232.

The modulation symbols for respective data streams are then provided toa TX MIMO processor 220, which can further process the modulationsymbols (e.g., for OFDM). The TX MIMO processor 220 then provides NTmodulation symbol streams to NT transmitters (TMTR) 222 a through 222 t.In certain aspects, the TX MIMO processor 220 applies beamformingweights to the symbols of the data streams and to the antenna from whichthe symbol is being transmitted.

Each transmitter 222 receives and processes a respective symbol streamto provide one or more analog signals, and further conditions (e.g.,amplifies, filters, and upconverts) the analog signals to provide amodulated signal suitable for transmission over the MIMO channel. NTmodulated signals from the transmitters 222 a through 222 t are thentransmitted from NT antennas 224 a through 224 t, respectively.

At a receiver system 250, the transmitted modulated signals are receivedby NR antennas 252 a through 252 r and the received signal from eachantenna 252 is provided to a respective receiver (RCVR) 254 a through254 r. Each receiver 254 conditions (e.g., filters, amplifies, anddownconverts) a respective received signal, digitizes the conditionedsignal to provide samples, and further processes the samples to providea corresponding “received” symbol stream.

An RX data processor 260 then receives and processes the NR receivedsymbol streams from NR receivers 254 based on a particular receiverprocessing technique to provide NR “detected” symbol streams. The RXdata processor 260 then demodulates, deinterleaves, and decodes eachdetected symbol stream to recover the traffic data for the data stream.The processing by the RX data processor 260 is complementary to theprocessing performed by the TX MIMO processor 220 and the TX dataprocessor 214 at the transmitter system 210.

A processor 270 (operating with a memory 272) periodically determineswhich pre-coding matrix to use (discussed below). The processor 270formulates an uplink message having a matrix index portion and a rankvalue portion.

The uplink message can include various types of information regardingthe communication link and/or the received data stream. The uplinkmessage is then processed by a TX data processor 238, which alsoreceives traffic data for a number of data streams from a data source236, modulated by a modulator 280, conditioned by transmitters 254 athrough 254 r, and transmitted back to the transmitter system 210.

At the transmitter system 210, the modulated signals from the receiversystem 250 are received by antennas 224, conditioned by receivers 222,demodulated by a demodulator 240, and processed by an RX data processor242 to extract the uplink message transmitted by the receiver system250. The processor 230 then determines which pre-coding matrix to usefor determining the beamforming weights, then processes the extractedmessage.

FIG. 3 is a block diagram conceptually illustrating an exemplary framestructure in downlink Long Term Evolution (LTE) communications. Thetransmission timeline for the downlink may be partitioned into units ofradio frames. Each radio frame may have a predetermined duration (e.g.,10 milliseconds (ms)) and may be partitioned into 10 subframes withindices of 0 through 9. Each subframe may include two slots. Each radioframe may thus include 20 slots with indices of 0 through 19. Each slotmay include L symbol periods, e.g., 7 symbol periods for a normal cyclicprefix (as shown in FIG. 3) or 6 symbol periods for an extended cyclicprefix. The 2L symbol periods in each subframe may be assigned indicesof 0 through 2L−1. The available time frequency resources may bepartitioned into resource blocks. Each resource block may cover Nsubcarriers (e.g., 12 subcarriers) in one slot.

In LTE, an eNB may send a Primary Synchronization Signal (PSS) and aSecondary Synchronization Signal (SSS) for each cell in the eNB. The PSSand SSS may be sent in symbol periods 6 and 5, respectively, in each ofsubframes 0 and 5 of each radio frame with the normal cyclic prefix, asshown in FIG. 3. The synchronization signals may be used by UEs for celldetection and acquisition. The eNB may send a Physical Broadcast Channel(PBCH) in symbol periods 0 to 3 in slot 1 of subframe 0. The PBCH maycarry certain system information.

The eNB may send a Cell-specific Reference Signal (CRS) for each cell inthe eNB. The CRS may be sent in symbols 0, 1, and 4 of each slot in caseof the normal cyclic prefix, and in symbols 0, 1, and 3 of each slot incase of the extended cyclic prefix. The CRS may be used by UEs forcoherent demodulation of physical channels, timing and frequencytracking, Radio Link Monitoring (RLM), Reference Signal Received Power(RSRP), and Reference Signal Received Quality (RSRQ) measurements, etc.

The eNB may send a Physical Control Format Indicator Channel (PCFICH) inthe first symbol period of each subframe, as seen in FIG. 3. The PCFICHmay convey the number of symbol periods (M) used for control channels,where M may be equal to 1, 2 or 3 and may change from subframe tosubframe. M may also be equal to 4 for a small system bandwidth, e.g.,with less than 10 resource blocks. In the example shown in FIG. 3, M=3.The eNB may send a Physical HARQ Indicator Channel (PHICH) and aPhysical Downlink Control Channel (PDCCH) in the first M symbol periodsof each subframe. The PDCCH and PHICH are also included in the firstthree symbol periods in the example shown in FIG. 3. The PHICH may carryinformation to support Hybrid Automatic Repeat Request (HARQ). The PDCCHmay carry information on resource allocation for UEs and controlinformation for downlink channels. The eNB may send a Physical DownlinkShared Channel (PDSCH) in the remaining symbol periods of each subframe.The PDSCH may carry data for UEs scheduled for data transmission on thedownlink. The various signals and channels in LTE are described in 3GPPTS 36.211, entitled “Evolved Universal Terrestrial Radio Access(E-UTRA); Physical Channels and Modulation,” which is publiclyavailable.

The eNB may send the PSS, SSS and PBCH in the center 1.08 MHz of thesystem bandwidth used by the eNB. The eNB may send the PCFICH and PHICHacross the entire system bandwidth in each symbol period in which thesechannels are sent. The eNB may send the PDCCH to groups of UEs incertain portions of the system bandwidth. The eNB may send the PDSCH tospecific UEs in specific portions of the system bandwidth. The eNB maysend the PSS, SSS, PBCH, PCFICH and PHICH in a broadcast manner to allUEs, may send the PDCCH in a unicast manner to specific UEs, and mayalso send the PDSCH in a unicast manner to specific UEs.

A number of resource elements may be available in each symbol period.Each resource element may cover one subcarrier in one symbol period andmay be used to send one modulation symbol, which may be a real orcomplex value. Resource elements not used for a reference signal in eachsymbol period may be arranged into resource element groups (REGs). EachREG may include four resource elements in one symbol period. The PCFICHmay occupy four REGs, which may be spaced approximately equally acrossfrequency, in symbol period 0. The PHICH may occupy three REGs, whichmay be spread across frequency, in one or more configurable symbolperiods. For example, the three REGs for the PHICH may all belong insymbol period 0 or may be spread in symbol periods 0, 1 and 2. The PDCCHmay occupy 9, 18, 32 or 64 REGs, which may be selected from theavailable REGs, in the first M symbol periods. Only certain combinationsof REGs may be allowed for the PDCCH.

A UE may know the specific REGs used for the PHICH and the PCFICH. TheUE may search different combinations of REGs for the PDCCH. The numberof combinations to search is typically less than the number of allowedcombinations for the PDCCH. An eNB may send the PDCCH to the UE in anyof the combinations that the UE will search.

FIG. 4 is a block diagram conceptually illustrating an exemplary framestructure in uplink Long Term Evolution (LTE) communications. Theavailable Resource Blocks (RBs) for the uplink may be partitioned into adata section and a control section. The control section may be formed atthe two edges of the system bandwidth and may have a configurable size.The resource blocks in the control section may be assigned to UEs fortransmission of control information. The data section may include allresource blocks not included in the control section. The design in FIG.4 results in the data section including contiguous subcarriers, whichmay allow a single UE to be assigned all of the contiguous subcarriersin the data section.

A UE may be assigned resource blocks in the control section to transmitcontrol information to an eNB. The UE may also be assigned resourceblocks in the data section to transmit data to the eNodeB. The UE maytransmit control information in a Physical Uplink Control Channel(PUCCH) on the assigned resource blocks in the control section. The UEmay transmit only data or both data and control information in aPhysical Uplink Shared Channel (PUSCH) on the assigned resource blocksin the data section. An uplink transmission may span both slots of asubframe and may hop across frequency as shown in FIG. 4.

The PSS, SSS, CRS, PBCH, PUCCH and PUSCH in LTE are described in 3GPP TS36.211, entitled “Evolved Universal Terrestrial Radio Access (E-UTRA);Physical Channels and Modulation,” which is publicly available.

In an aspect, described herein are systems and methods for providingsupport within a wireless communication environment, such as a 3GPP LTEenvironment or the like, to facilitate multi-radio coexistencesolutions.

Referring now to FIG. 5, illustrated is an example wirelesscommunication environment 500 in which various aspects described hereincan function. The wireless communication environment 500 can include awireless device 510, which can be capable of communicating with multiplecommunication systems. These systems can include, for example, one ormore cellular systems 520 and/or 530, one or more WLAN systems 540and/or 550, one or more wireless personal area network (WPAN) systems560, one or more broadcast systems 570, one or more satellitepositioning systems 580, other systems not shown in FIG. 5, or anycombination thereof. It should be appreciated that in the followingdescription the terms “network” and “system” are often usedinterchangeably.

The cellular systems 520 and 530 can each be a CDMA, TDMA, FDMA, OFDMA,Single Carrier FDMA (SC-FDMA), or other suitable system. A CDMA systemcan implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) andother variants of CDMA. Moreover, cdma2000 covers IS-2000 (CDMA2000 1X),IS-95 and IS-856 (HRPD) standards. A TDMA system can implement a radiotechnology such as Global System for Mobile Communications (GSM),Digital Advanced Mobile Phone System (D-AMPS), etc. An OFDMA system canimplement a radio technology such as Evolved UTRA (E-UTRA), Ultra MobileBroadband (UMB), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSMare described in documents from an organization named “3rd GenerationPartnership Project” (3GPP). cdma2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). In an aspect, the cellular system 520 can include a number ofbase stations 522, which can support bi-directional communication forwireless devices within their coverage. Similarly, the cellular system530 can include a number of base stations 532 that can supportbi-directional communication for wireless devices within their coverage.

WLAN systems 540 and 550 can respectively implement radio technologiessuch as IEEE 802.11 (WiFi), Hiperlan, etc. The WLAN system 540 caninclude one or more access points 542 that can support bi-directionalcommunication. Similarly, the WLAN system 550 can include one or moreaccess points 552 that can support bi-directional communication. TheWPAN system 560 can implement a radio technology such as Bluetooth (BT),IEEE 802.15, etc. Further, the WPAN system 560 can supportbi-directional communication for various devices such as wireless device510, a headset 562, a computer 564, a mouse 566, or the like.

The broadcast system 570 can be a television (TV) broadcast system, afrequency modulation (FM) broadcast system, a digital broadcast system,etc. A digital broadcast system can implement a radio technology such asMediaFLO™, Digital Video Broadcasting for Handhelds (DVB-H), IntegratedServices Digital Broadcasting for Terrestrial Television Broadcasting(ISDB-T), or the like. Further, the broadcast system 570 can include oneor more broadcast stations 572 that can support one-way communication.

The satellite positioning system 580 can be the United States GlobalPositioning System (GPS), the European Galileo system, the RussianGLONASS system, the Quasi-Zenith Satellite System (QZSS) over Japan, theIndian Regional Navigational Satellite System (IRNSS) over India, theBeidou system over China, and/or any other suitable system. Further, thesatellite positioning system 580 can include a number of satellites 582that transmit signals for position determination.

In an aspect, the wireless device 510 can be stationary or mobile andcan also be referred to as a user equipment (UE), a mobile station, amobile equipment, a terminal, an access terminal, a subscriber unit, astation, etc. The wireless device 510 can be cellular phone, a personaldigital assistance (PDA), a wireless modem, a handheld device, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, etc. Inaddition, a wireless device 510 can engage in two-way communication withthe cellular system 520 and/or 530, the WLAN system 540 and/or 550,devices with the WPAN system 560, and/or any other suitable systems(s)and/or devices(s). The wireless device 510 can additionally oralternatively receive signals from the broadcast system 570 and/orsatellite positioning system 580. In general, it can be appreciated thatthe wireless device 510 can communicate with any number of systems atany given moment. Also, the wireless device 510 may experiencecoexistence issues among various ones of its constituent radio devicesthat operate at the same time. Accordingly, device 510 includes acoexistence manager (CxM, not shown) that has a functional module todetect and mitigate coexistence issues, as explained further below.

Turning next to FIG. 6, a block diagram is provided that illustrates anexample design for a multi-radio wireless device 600 and may be used asan implementation of the radio 510 of FIG. 5. As FIG. 6 illustrates, thewireless device 600 can include N radios 620 a through 620 n, which canbe coupled to N antennas 610 a through 610 n, respectively, where N canbe any integer value. It should be appreciated, however, that respectiveradios 620 can be coupled to any number of antennas 610 and thatmultiple radios 620 can also share a given antenna 610.

In general, a radio 620 can be a unit that radiates or emits energy inan electromagnetic spectrum, receives energy in an electromagneticspectrum, or generates energy that propagates via conductive means. Byway of example, a radio 620 can be a unit that transmits a signal to asystem or a device or a unit that receives signals from a system ordevice. Accordingly, it can be appreciated that a radio 620 can beutilized to support wireless communication. In another example, a radio620 can also be a unit (e.g., a screen on a computer, a circuit board,etc.) that emits noise, which can impact the performance of otherradios. Accordingly, it can be further appreciated that a radio 620 canalso be a unit that emits noise and interference without supportingwireless communication.

In an aspect, respective radios 620 can support communication with oneor more systems. Multiple radios 620 can additionally or alternativelybe used for a given system, e.g., to transmit or receive on differentfrequency bands (e.g., cellular and PCS bands).

In another aspect, a digital processor 630 can be coupled to radios 620a through 620 n and can perform various functions, such as processingfor data being transmitted or received via the radios 620. Theprocessing for each radio 620 can be dependent on the radio technologysupported by that radio and can include encryption, encoding,modulation, etc., for a transmitter; demodulation, decoding, decryption,etc., for a receiver, or the like. In one example, the digital processor630 can include a CxM 640 that can control operation of the radios 620in order to improve the performance of the wireless device 600 asgenerally described herein. The CxM 640 can have access to a database644, which can store information used to control the operation of theradios 620. As explained further below, the CxM 640 can be adapted for avariety of techniques to decrease interference between the radios. Inone example, the CxM 640 requests a measurement gap pattern or DRX cyclethat allows an ISM radio to communicate during periods of LTEinactivity.

For simplicity, digital processor 630 is shown in FIG. 6 as a singleprocessor. However, it should be appreciated that the digital processor630 can include any number of processors, controllers, memories, etc. Inone example, a controller/processor 650 can direct the operation ofvarious units within the wireless device 600. Additionally oralternatively, a memory 652 can store program codes and data for thewireless device 600. The digital processor 630, controller/processor650, and memory 652 can be implemented on one or more integratedcircuits (ICs), application specific integrated circuits (ASICs), etc.By way of specific, non-limiting example, the digital processor 630 canbe implemented on a Mobile Station Modem (MSM) ASIC.

In an aspect, the CxM 640 can manage operation of respective radios 620utilized by wireless device 600 in order to avoid interference and/orother performance degradation associated with collisions betweenrespective radios 620. CxM 640 may perform one or more processes, suchas that illustrated in FIG. 12. By way of farther illustration, a graph700 in FIG. 7 represents respective potential collisions between sevenexample radios in a given decision period. In the example shown in graph700, the seven radios include a WLAN transmitter (Tw), an LTEtransmitter (TI), an FM transmitter (Tf), a GSM/WCDMA transmitter(Tc/Tw), an LTE receiver (Rl), a Bluetooth receiver (Rb), and a GPSreceiver (Rg). The four transmitters are represented by four nodes onthe left side of the graph 700. The four receivers are represented bythree nodes on the right side of the graph 700.

A potential collision between a transmitter and a receiver isrepresented on the graph 700 by a branch connecting the node for thetransmitter and the node for the receiver. Accordingly, in the exampleshown in the graph 700, collisions may exist between (1) the WLANtransmitter (Tw) and the Bluetooth receiver (Rb); (2) the LTEtransmitter (Tl) and the Bluetooth receiver (Rb); (3) the WLANtransmitter (Tw) and the LTE receiver (Rl); (4) the FM transmitter (Tf)and the GPS receiver (Rg); (5) a WLAN transmitter (Tw), a GSM/WCDMAtransmitter (Tc/Tw), and a GPS receiver (Rg).

In one aspect, an example CxM 640 can operate in time in a manner suchas that shown by diagram 800 in FIG. 8. As diagram 800 illustrates, atimeline for CxM operation can be divided into Decision Units (DUs),which can be any suitable uniform or non-uniform length (e.g., 100 μs)where notifications are processed, and a response phase (e.g., 20 μs)where commands are provided to various radios 620 and/or otheroperations are performed based on actions taken in the evaluation phase.In one example, the timeline shown in the diagram 800 can have a latencyparameter defined by a worst case operation of the timeline, e.g., thetiming of a response in the case that a notification is obtained from agiven radio immediately following termination of the notification phasein a given DU.

In-device coexistence problems can exist with respect to a UE betweenresources such as, for example, LTE and ISM bands (e.g., forBluetooth/WLAN). In current LTE implementations, any interference issuesto LTE are reflected in the DL measurements (e.g., Reference SignalReceived Quality (RSRQ) metrics, etc.) reported by a UE and/or the DLerror rate which the eNB can use to make inter-frequency or inter-RAThandoff decisions to, e.g., move LTE to a channel or RAT with nocoexistence issues. However, it can be appreciated that these existingtechniques will not work if, for example, the LTE UL is causinginterference to Bluetooth/WLAN but the LTE DL does not see anyinterference from Bluetooth/WLAN. More particularly, even if the UEautonomously moves itself to another channel on the UL, the eNB can insome cases handover the UE back to the problematic channel for loadbalancing purposes. In any case, it can be appreciated that existingtechniques do not facilitate use of the bandwidth of the problematicchannel in the most efficient way.

Turning now to FIG. 9, a block diagram of a system 900 for providingsupport within a wireless communication environment for multi-radiocoexistence management is illustrated. In an aspect, the system 900 caninclude one or more UEs 910 and/or eNBs 920, which can engage in UL, DL,and/or any other suitable communication with each other and/or any otherentities in the system 900. In one example, the UE 910 and/or eNB 920can be operable to communicate using a variety resources, includingfrequency channels and sub-bands, some of which can potentially becolliding with other radio resources (e.g., a Bluetooth radio). Thus,the UE 910 can utilize various techniques for managing coexistencebetween multiple radios utilized by the UE 910, as generally describedherein.

To mitigate at least the above shortcomings, the UE 910 can utilizerespective features described herein and illustrated by the system 900to facilitate support for multi-radio coexistence within the UE 910. Thevarious modules including the channel monitoring module 912, resourcecoexistence analyzer 914, frame offset module 916, LTE operation monitor918, and ISM operation monitor 919 and other modules may be configuredto implement the embodiments discussed below.

In a mobile communications user equipment (UE) there may be interferenceissues between a Long Term Evolution (LTE) radio (particularly in Band40 (2.3-2.4 GHz) and Band 7 (2.5 GHz)) and a radio used for industrial,scientific and medical (ISM) band communications (in particularBluetooth and wireless local area network (WLAN)). The interference isfurther complicated because LTE and Bluetooth (BT) are asynchronous withrespect to each other. One LTE frame including a receive/downlink (DL)subframe and a transmit/uplink (UL) subframe is 5 milliseconds. In thatsame time period Bluetooth has 8 time slots, alternating between receiveand transmit. If one radio is transmitting while the other is trying toreceive, there will be interference on the receive side.

FIG. 10 illustrates interference on a timeline for LTE Band 40 (TDD LTE(time division duplex LTE)) and Bluetooth with no coexistence manager.As shown, each LTE frame is 5 or 10 milliseconds long, depending on theLTE configuration. A 5 ms frame is illustrated, with three one mstimeslots of downlink receive (shown grouped as timeslots 1002) and twoone ms timeslots of uplink transmit (shown grouped as timeslots 1004).As illustrated, each Bluetooth enhanced synchronous connection oriented(eSCO) interval (between the arrows) consists of six timeslots (each 625microseconds long) beginning with a receive slot and alternating betweenreceive and transmit (transmit indicated with shading). In theillustration Bluetooth is configured to be in slave mode. Other eSCOconfigurations and Bluetooth traffic types are possible and may be usedwith the present disclosure. For purposes of FIG. 10, LTE is assumed tobe always operating. In each timeslot a check mark (✓) indicates whenBluetooth is successfully operating. An X indicates interference. Anoverlap between one radio's active transmit time slot with the other'sreceive time slot (and vice versa) will cause interference, resulting inan X. As illustrated, one active LTE transmit/receive timeslot mayinterfere with multiple Bluetooth receive/transmit timeslots. Becausethe time slots of the two radios are not synchronized, frequent andunpredictable interference occurs.

FIG. 11 illustrates interference on a timeline for LTE Band 7 (FDD LTE(frequency division duplex LTE)) with no coexistence manager. An Xindicates interference. In the example of FIG. 11, the interferenceoccurs between the LTE transmit slots and the Bluetooth receive slots.LTE is presumed to always be transmitting (as shown by the shaded LTEtimeslots). As shown, each Bluetooth receive (unshaded) timeslot usingan enhanced synchronous connection oriented (eSCO) plus acknowledge(+ACK) link, is interfered with by the LTE transmissions.

Several eSCO arbitration schemes may be considered to reduce theillustrated interference. For the examples discussed below, theBluetooth device in the UE is considered to be a slave.

In one arbitration scheme, no coexistence manager (CxM) is present. Thisscheme generally causes significant degradation to LTE downlinkcommunications and can also impair Bluetooth enhanced synchronousconnection oriented (eSCO) transmission, depending on the number ofretransmissions and LTE configuration. In another scheme LTE may begiven priority over Bluetooth, which would cause significantinterference with Bluetooth eSCO operation, as shown in FIG. 11. Inanother arbitration scheme Bluetooth may be given priority over LTE,however this may cause significant LTE performance degradation. A fourtharbitration scheme based on a history of UE transmissions/reception mayachieve similar results to a Bluetooth priority scheme due to high eSCOpacket error rate (PER) criteria.

Offered is a method to allow time division multiplexing (TDM)arbitration schemes between LTE and ISM (e.g., Bluetooth or WLAN)radios. The arbitration schemes can be customized for particular casesto achieve improved performance of the two radios by determiningpotential time slot configurations (i.e. selecting specific time slotsfor transmit or receive and preventing communications in other timeslots) and selecting a desired time slot configuration. Given stringentBluetooth latency requirements (which correspond to an eSCO interval),the method preserves Bluetooth transmission while reducing LTEdegradation. According to one aspect of the method, LTE has priority asoften as possible, with priority given to Bluetooth only in some cases.Bin jumping and LTE frame information may further improve the solution.Frame offset information may also be used to determine the improvedpriority for each of the Bluetooth slots in the eSCO interval. Frameoffset information may be used to align the desired time slotconfiguration to improve performance. Signal priorities may be chosen toreduce the impact to LTE performance (for example, choosing toprioritize a Bluetooth receive slot that only overlaps with one LTEtransmit slot). These priorities may change as the frame offset betweenthe radios changes.

In one aspect, the UE may assume that the minimum acceptable performancefor enhanced synchronous connection oriented (eSCO) is that ofsynchronous connection oriented (SCO) communications. While, this maynot be the case, the assumption will give a lower bound on LTEthroughput degradation, thus reducing LTE degradation while ensuringthat Bluetooth is allowed at least one transmit and one receive slot ineach eSCO interval. With each eSCO interval having six timeslots and twore-transmissions, there are only five ways for eSCO to succeed with onlyone transmit (T) and one receive (R) slot (where ‘X’ denotes a slot thatis not used or denied):

R T X X X X X X R T X X X X X X R T X T R X X X X T X X R X

The above potential time slot configurations apply due to certainpolling rules. The first two timeslots are reserved and permittransmission but otherwise the transmit timeslot immediately follows areceive timeslot while Bluetooth is in slave mode. A desired time slotconfiguration may be chosen to reduce interference between LTE andBluetooth while maintaining desired performance levels.

An approach assigning priority to various timeslots may then be used.For a given eSCO configuration, the CxM may identify equivalent SCOsequences. For each eSCO interval and for each equivalent SCO sequence,the CxM may identify the number of conflicting LTE transmit sub-framesand LTE receive sub-frames that would be denied if a particularBluetooth sequence was given higher priority than LTE. The CxM may thenchoose the Bluetooth sequence with a reduced or minimum LTE interruptionor degradation and apply priority assignments for the appropriatetransmit and receive slots to allow Bluetooth operation while reducingLTE interruption. LTE degradation may be determined in a number of waysincluding the sum of transmit and receive degraded slots, but it mayalso be determined using a weighted sum. The above prioritydeterminations may repeat whenever a frame offset changes, for exampleafter four eSCO intervals if the overall timing offset between LTE andBluetooth remains the same. If it is possible to stop LTE transmissions,the above approach may also be used to select LTE subframes that shouldnot transmit, thereby reducing overlap with Bluetooth communications.

The above techniques may avoid instances where granting a Bluetooth slotdenies two LTE sub-frames. Further, the above techniques may be appliedto both LTE bands (e.g., Band 7 (2.5 GHz) and Band 40 (2.3-2.4 GHz)adjacent to the ISM bands. Other information may also be used to improveperformance. For example, if particular slots are transmitted orreceived on channels that are prone to interference, bin jumping may beapplied to give higher priority to slots with channels less prone tointerference. Information on transmit power or received signal strengthindication (RSSI) may also be used to prioritize certain time slots.

As shown in FIG. 12, a coexistence manager may determine a coexistencepolicy for communication resource operation within a user equipment(UE). At block 1202 a frame offset between communications of a firstcommunication resource (e.g., an LTE radio) and communications of asecond communication resource (e.g., a Bluetooth or WLAN radio) isdetermined. At block 1204, potential time slot configurations aredetermined for the communications of the second communication resource.At block 1206, a time slot configuration is selected and communicationsare controlled based on the selected time slot configuration and thedetermined frame offset. In one example, a time slot configuration isselected from the determined potential time slot configurations, toreduce degradation of the first communication resource due toconflicting time slots between the first communication resource and thesecond communication resource, based on the determined frame offset.

The examples above describe aspects implemented in an LTE system.However, the scope of the disclosure is not so limited. Various aspectsmay be adapted for use with other communication systems, such as thosethat employ any of a variety of communication protocols including, butnot limited to, CDMA systems, TDMA systems, FDMA systems, and OFDMAsystems. Similarly, although the description is with respect toBluetooth, it should appreciated that the present disclosure is equallyapplicable to other technologies, e.g., WLAN.

In one configuration, the UE configured for wireless communicationincludes means for determining a frame offset, means for determiningpotential time slot configurations, and means for selecting a time slotconfiguration. In one aspect, the aforementioned means may be theresource coexistence analyzer 914, and/or the frame offset module 916configured to perform the functions recited by the aforementioned means.In another aspect, the aforementioned means may be a module or anyapparatus configured to perform the functions recited by theaforementioned means.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an example of exemplary approaches. Based upondesign preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged while remainingwithin the scope of the present disclosure. The accompanying methodclaims present elements of the various steps in a sample order, and arenot meant to be limited to the specific order or hierarchy presented.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the aspects disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a user terminal. In the alternative, the processor and thestorage medium may reside as discrete components in a user terminal.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other aspects without departing from the spirit or scope ofthe disclosure. Thus, the present disclosure is not intended to belimited to the aspects shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

What is claimed is:
 1. A method of arbitrating between wirelesscommunications of different radio access technologies, comprising:determining, by a wireless device, a frame offset between communicationsof a first radio modem of the wireless device and communications of asecond radio modem of the wireless device, the communications of thefirst radio modem asynchronous with the communications of the secondradio modem; determining, by the wireless device, a plurality ofpotential time slot configurations that may be used for an interval ofthe communications of the second radio modem, each of the plurality ofpotential time slot configurations comprising a receive time slot, atransmit time slot, and at least one time slot that is not used or whoseusage is denied in accordance with polling rules, a sequence of timeslots in each of the potential time slot configurations being equivalentbut different relative to other potential time slot configurations ofthe plurality of potential time slot configurations; determining, by thewireless device, for each of a plurality of the intervals of thecommunications of the second radio modem and for each potential timeslot configuration of the plurality of potential time slotconfigurations that may be used for a respective interval, a number ofthe receive time slots of the first radio modem that would be degradedif a respective potential time slot configuration was given priorityover the receive time slots of the first radio modem, based at least inpart on the frame offset, and a number of transmit time slots of thefirst radio modem that would be degraded if the respective potentialtime slot configuration was given priority over the transmit time slotsof the first radio modem, based at least in part on the frame offset;selecting, by the wireless device, a time slot configuration from theplurality of potential time slot configurations that would result inless degradation to communications of the first radio modem than otherpotential time slot configurations, based on the number of receive timeslots and the number of transmit time slots that would be degraded; andcontrolling communications of the second radio modem using the time slotconfiguration until a change in an overall timing offset between thecommunications of the first radio modem and the communications of thesecond radio modem changes the frame offset, reducing degradation of thecommunications of the first radio modem due to conflicting time slotsbetween communications of the first radio modem and the second radiomodem.
 2. The method of claim 1, further comprising: stoppingtransmission of the first radio modem during conflicting subframes. 3.The method of claim 1, in which the conflicting occurs when atransmission from the first radio modem occurs at the same time asreceiving at the second radio modem and also when receiving at the firstradio modem at the same time as transmitting from the second radiomodem.
 4. The method of claim 1, in which each potential time slotconfiguration comprises a single transmit time slot and a single receivetime slot within the interval.
 5. The method of claim 1, in which thesecond radio modem comprises an ISM modem and the first radio modemcomprises an LTE modem.
 6. The method of claim 5, in which the ISM modemis a Bluetooth modem and the plurality of potential time slotconfigurations are enhanced synchronous connection oriented (eSCO) timeslot configurations.
 7. The method of claim 1, in which the selecting ofthe time slot configuration prioritizes scheduling communications usingtime slots with improved performance.
 8. An apparatus operable in awireless communication system, the apparatus comprising: means fordetermining a frame offset between communications of a firstcommunication resource and communications of a second communicationresource, the communications of the first communication resource beingasynchronous with the communications of the second communicationresource; means for determining a plurality of potential time slotconfigurations that may be used for an interval of the communications ofthe second communication resource, each of the plurality of potentialtime slot configurations comprising a receive time slot, a transmit timeslot, and at least one time slot that is not used or whose usage isdenied in accordance with polling rules, a sequence of time slots ineach of the potential time slot configurations being equivalent butdifferent relative to other potential time slot configurations of theplurality of potential time slot configurations; means for determining,for each of a plurality of the intervals of the communications of thesecond communication resource and for each potential time slotconfiguration of the plurality of potential time slot configurationsthat may be used for a respective interval, a number of receive timeslots of the first communication resource that would be degraded if arespective potential time slot configuration was given priority over thereceive time slots of the first communication resource, based at leastin part on the frame offset, and a number of transmit time slots of thefirst communication resource that would be degraded if the respectivepotential time slot configuration was given priority over the transmittime slots of the first communication resource, based at least in parton the frame offset; and means for selecting a time slot configurationof the plurality of potential time slot configurations that would resultin less degradation to communications of the first communicationresource than other potential time slot configurations, based on thenumber of receive time slots and the number of transmit time slots thatwould be degraded; and means for controlling communications of thesecond communication resource using the time slot configuration until achange in an overall timing offset between the communications of thefirst communication resource and communications of the secondcommunication resource changes the frame offset, reducing degradation ofthe first communication resource due to conflicting time slots betweenthe first communication resource and the second communication resource.9. The apparatus of claim 8, further comprising means for stoppingtransmission of the first communication resource during conflictingsubframes.
 10. The apparatus of claim 8, in which each potential timeslot configuration comprises a single transmit time slot and a singlereceive time slot within the interval.
 11. A computer program productconfigured for wireless communication, the computer program productcomprising: a non-transitory computer-readable storage program coderecorded thereon, the program code comprising: program code to determinea frame offset between communications of a first communication resourceand communications of a second communication resource, thecommunications of the first communication resource being asynchronouswith the communications of the second communications resource; programcode to determine a plurality of potential time slot configurations thatmay be used for an interval of the communications of the secondcommunication resource, each of the plurality of potential time slotconfigurations comprising a receive time slot, a transmit time slot, andat least one time slot that is not used or whose usage is denied inaccordance with polling rules, a sequence of time slots in each of thepotential time slot configurations being equivalent but differentrelative to other potential time slot configurations of the plurality ofpotential time slot configurations; program code to determine, for eachof a plurality of the intervals of the communications of the secondcommunication resource and for each potential time slot configuration ofthe plurality of potential time slot configurations that may be used fora respective interval, a number of receive time slots of the firstcommunication resource that would be degraded if a respective potentialtime slot configuration was given priority over the time slots of thefirst communication resource, based at least in part on the frameoffset, and a number of transmit time slots of the first communicationresource that would be degraded if the respective potential time slotconfiguration was given priority over transmit time slots of the firstcommunication resource, based at least in part on the frame offset; andprogram code to select a time slot configuration from the plurality ofpotential time slot configurations that would result in less degradationto communications of the first communication resource than otherpotential time slot configurations, based on the number of the receivetime slots and the number of transmit time slots that would be degraded;and program code to control communications of the second communicationresource using the time slot configuration until a change in an overalltiming offset between the communications of the first communicationresource and the communications of the second communication resourcechanges the frame offset, reducing degradation of the firstcommunication resource due to conflicting time slots between the firstcommunication resource and the second communication resource.
 12. Thecomputer program product of claim 11, in which the program code furthercomprises program code to stop transmission of the first communicationresource during conflicting subframes.
 13. The computer program productof claim 11, in which each potential time slot configuration comprises asingle transmit time slot and a single receive time slot within theinterval.
 14. An apparatus configured for operation in a wirelesscommunication network, the apparatus comprising: a memory; and at leastone processor coupled to memory, the at least one processor beingconfigured: to determine a frame offset between communications of afirst communication resource and communications of a secondcommunication resource, the communications of the first communicationresource being asynchronous with the communications of the second radioresource; to determine a plurality of potential time slot configurationsthat may be used for an interval of the communications of the secondcommunication resource, each of the plurality of potential time slotconfigurations comprising a receive time slot, a transmit time slot, andat least one time slot that is not used or whose usage is denied inaccordance with polling rules, a sequence of time slots in each of thepotential time slot configurations being equivalent but differentrelative to other potential time slot configurations of the plurality ofpotential time slot configurations; to determine, for each of aplurality of intervals of the communications of the second communicationresource, based at least in part on the frame offset, and for eachpotential time slot configuration of the plurality of potential timeslot configurations that may be used for a respective interval, a numberof receive time slots of the first communication resource that would bedegraded if a respective potential time slot configuration was givenpriority over the receive time slots of the first communicationresource, based at least in part on the frame offset, and a number oftransmit time slots of the first communication resource that would bedegraded if the respective potential time slot configuration was givenpriority over the transmit time slots of the first communicationresource, based at least in part on the frame offset; and to select atime slot configuration of the plurality of potential time slotconfigurations that would result in less degradation to communicationsof the first communication resource than other potential time slotconfigurations, based on the number of receive time slots and the numberof transmit time slots that would be degraded; and to controlcommunications of the second communication resource using the time slotconfiguration until a change in overall timing offset between thecommunications of the first communication resource and thecommunications of the second communication resource changes the frameoffset, reducing degradation of the first communication resource due toconflicting time slots between the first communication resource and thesecond communication resource.
 15. The apparatus of claim 14, in whichthe at least one processor is further configured to stop transmission ofthe first communication resource during conflicting subframes.
 16. Theapparatus of claim 14, which the conflicting occurs when a transmissionfrom the first communication resource occurs at the same time asreceiving at the second communications resource and also when receivingat the first communication resource at the same time as transmittingfrom the second communications resource.
 17. The apparatus of claim 14,in which each potential time slot configuration comprises a singletransmit time slot and a single receive time slot within the interval.18. The apparatus of claim 14 in which the second communication resourcecomprises an ISM modem and the first communication resource comprises anLTE modem.
 19. The apparatus of claim 18, in which the ISM modem is aBluetooth modem and the plurality of potential time slot configurationsare enhanced synchronous connection oriented (eSCO) time slotconfigurations.
 20. The apparatus of claim 14 in which the at least oneprocessor selects the first time slot configuration which gives priorityto scheduling communications using time slots with improved performance.